Grinding wheel and treatment thereof



wear than heretofore.

Patented Mar. 10, 1936 UNITED STATES GRINDING WHEEL AND TREATDIENTTHEREOF Nils Gunnar Anderson and Axel Fredrik Thure Lofquist, Malmo,Sweden, assignors to Norton Company, Worcester, Mass.

No Drawing.

Application November 19, 1935,

Serial No. 50,568. In Sweden December 5,

8 Claims.

The invention relates to grinding wheels and a treatment thereof toimprove their quality.

One object of the invention is to provide a faster cutting grinding.wheel.

can be applied to already manufactured grinding wheels to increase therate of cutting thereof. Another object of the invention is to providean improved filler for a grinding wheel. Another object of the inventionis to provide an improved snagging wheel. Another object of theinvention is to provide an improved wheel for grinding stainless steel.'Another object of the invention is to provide a treatment for wheelswhich shall improve their action in dry grinding. Another object of theinvention is to provide a grinding wheel, and/or a treatment for agrinding wheel, which enables it to remove a greater amount of stock fora given amount of wheel Other objects will be in part obvious or in partpointed out hereinafter. The invention accordingly consists in thefeatures of construction, combinations of elements, and in the severalsteps and relation and order of each of said steps to one or more, of

the others thereof, all as will be illustratively described herein, andthe scope of the application of which will be indicated in the followingclaims.

We provide a grinding wheel. The invention is not limited to any size,shape, or type of grinding wheel. We prefer to provide a relativelyporous grinding wheel, such as one of the wheels bonded with any knownvitrified or ceramic bond. Such a wheel may be made according to anyknown method. The wheel is completely formed or fired or the bondotherwise set prior to the treatment now to be described, so far as thepreferred form of our invention is concerned.

Having formed the grinding wheel we make a solution, preferably a watersolution, of a deliquescent salt. Any one of the chlorides,

sulphides, nitrates, carbonates, or acetates which are deliquescent maybe used. Excellent results have been achieved in practice from the useof zinc chloride, and calcium chloride, which is a somewhat cheaper saltand also highly deliquescent, may be used to great advantage.

The solution need not be a saturated solution but should be a strongsolution. Other than that there is no critical point, as the object isto introduce a deposit into the wheel and whatever method introduces asubstantial deposit Another object of the invention is to provide atreatment which into the wheel is a good method in actual practice.

Having made the solution we place the grinding wheel in it,-or pour itover the grinding wheel. Having thoroughly wet the grinding wheel withthe salt solution, the excess over and above what remains by capillaryaction is removed by spinning the wheel. However, the wheel should bespun at a slow speed for a short time in order not to remove too much ofthe liquid. The wheel may then be allowed to dry to some extent ifdesired. Usually the wheel still contains much moisture when it is usedon account of the deliquescence of the salt.

The wheel may now be used for snagging castings or for any other purposewhere no supply of water is provided. When so used it is found that thewheel grinds as much as 66% faster than an untreated wheel of the samegrade and structure otherwise. The wheel has a freer cutting action.While the treatment herein described increases the wheel wear somewhat,this increase is far less than the increase in the rate of cutting andconsequently for a given amount of wheel wear there will be a greateramount of material removed according to this invention.

The wheel is also particularly useful in the cutting ofv stainlesssteel. It appears that the impregnation of the wheel with a deliquescentsalt to a certain extent reduces glazing. Probably also there is alubricating action. But whatever the theory, and we do not wish to beheld to the foregoing theories, greatly improved results are achieved.

It will thus be seen that there has been provided by this invention amethod and an article in which the various objects hereinabove set forthtogether with many thoroughly practical advantages are successfullyachieved. As various possible embodiments might be made of themechanical freatures of the above invention and as the art hereindescribed might be varied in various parts, all without departing fromthe scope of the invention, it is to be understood that all matterhereinbefore set forth is to be interpreted as illustrative and not in alimiting sense.

We claim:

1. Method according to the invention which comprises forming a grindingwheel including completely setting the bond thereof, preparing asolution of a deliquescent salt, bringing the wheel and the solutiontogether to impregnate the wheel with the solution, and spinning thewheel to remove excess solution.

10 cent chloride.

6. As a new article of manufacture, a vitrified ceramic bonded grindingwheel having in its pores a deposit of a deliquescent salt.

7. As a new article of manufacture, a vitrified ceramic bonded grindingwheel having in its pores a deposit of a deliquescent chloride.

8. As a new article of manufacture, a grinding wheel having in its poresa deposit of zinc chloride.

NHS GUNNAR ANDERSON. AXEL FREDRE THURE LOFQUIST.

